<header>
  <div class="headerBox">
    <div class="topLogo vertical">logo</div>
    <ul class="navbar vertical fr">
      <li @@if (context.index=='active' ) { class="nav_active" }>
        <a href="./index.html">网站首页</a>
      </li>
      <li @@if (context.about=='active' ) { class="nav_active" }>
        <a href="about.html">产品与服务</a>
      </li>
      <li @@if (context.contact=='active' ) { class="nav_active" }>
        <a href="contact.html">关于我们</a>
      </li>
      <li @@if (context.contact=='active' ) { class="nav_active" }>
        <a href="contact.html">加入我们</a>
      </li>
    </ul>
  </div>
</header>
